France, mistaking the main line of the German advance, massed the main army of her forces along the upper Meuse from Belfort, two hundred miles away from the right position.
Britain's first blunder was in not being prepared to immediately help Belgium. So the Krupp monsters smashed that Belgian gate and the German hordes swept towards Paris.
Britain somewhat retrieved her delay by quickly rushing to block the triumphant tide of Germany. And two British army corps saved the war by holding up five of Germany's best armies at Mons; holding them whilst they waited for the French to move up from their first mistakenly-held position; till, finding that aid not forthcoming, they fought back to the Marne.
Germany now blundered once again. Its aerial scouts failed to see a great French army coming at its right flank; failed to note it, because it came so swiftly out from behind Paris. It drove the German right towards its centre, past the British forces, which, catching the Germans on their flank, smashed them back to the readied trenches on the Aisne Ridge.
Then the Germans came round the north of Belgium, and Britain blundered again in sending a force of marines and reserves to hold Antwerp. They had to ignominiously retire as they found the country too flat for offensive manœuvring, and they had arrived too late to do the necessary extensive trenching which really meant the making of artificial land contours. That British force, however, helped to cover the retreat of the Belgian army.
Germany's final mistake was holding their position on the ridge of the Aisne. It could not have retreated without fearful loss as that ridge was the last conformation of any military value in the practically flat country between the Aisne and Liege.
After the war, experts maintained that it would, for many reasons, have been better strategy for Germany not to have crossed the Meuse in the first place.
The Germans were fired with the false idea that the capture of Paris meant the end of French aggression.
They had forgotten the lesson they learnt in 1870, when the capture of Paris did not end that campaign. They had forgotten the lessons of the Boer War, that the capture of the South African capitals did not terminate that long struggle.
They had their fixed plan. It had been prepared many years before and been put away till required, though military strategy had moved along in the meantime. At the first blast of war they blindly threw themselves across Belgium with their battle cry of 34 years before: "A Paris."